Search: propose a few changes to look & feel

[humitos]

I think search is a really powerful addon, but it doesn't look great. My idea here is to propose some updates without changing the layout if possible to look a little nicer.

Current look and feel

• https://sphinx-rtd-theme.readthedocs.io/en/stable/configuring.html

External examples

Algolia with sidebar

• https://www.algolia.com/doc/?q=testing

Algolia simple

• https://docsearch.algolia.com/docs/what-is-docsearch/

Algolia integrated with Sphinx

https://sphinx-docsearch.readthedocs.io/

Material for MkDocs

• https://squidfunk.github.io/mkdocs-material/

[humitos]

This would be my initial suggestions to reduce the noise and focus the attention on the results. cc @agjohnson

[humitos]

I went ahead and opened a PR with my suggestions: #497